The present invention relates to an apparatus and a method for observing the progress in time of an object program executed by a computer system.
Such a method is of great significance for assessing the performance, for example recognizing and eliminating bottlenecks or for optimally dimensioning computer systems and for analyzing programming errors of the programs executed in the computer systems. In this connection, however, the progress in time of the programs must not be affected by the observation. The programs running are subjected to hard boundary conditions with respect to time, particularly in process control engineering, so that in this case the observation of the program run should, in practice, occur under real-time conditions. This is particularly problematic in multi-processor systems and computer networks
Methods of the type initially mentioned are known, for example, from Informatik-Spektrum (1985) 8, pages 37-40. In comparatively simple computers, the progress in time of an object program running on this computer can be directly and completely traced by applying a measuring probe of an electronic measuring instrument to hardware test points, such as address, data or control lines of an object computer This is no longer possible in complex computers since the information needed for executing the program is no longer conducted directly via lines into the central arithmetic and logic unit. In such computers, additional software is generally used for observing the program run, which runs alternately with the object program executed in the computer system. However, this delays the progress in time of the object program.